n. (Gr. pteris, fern; phyton, plant) a major division of the plant kingdom, having clear alternation of generations with a dominant vascular sporophyte initially dependent upon the gametophyte which is very reduced.

Plant in which the sporophyte generation is the larger phase and in which the gametophyte lives an existence independent of its parent sporophyte. Pteridophytes are almost all vascular plants, and include the lycophytes, trimerophytes, sphenophytes, and ferns.